JP5159287B2 - Image shake correction apparatus, imaging apparatus, and image shake correction apparatus control method - Google Patents

Description

The present invention relates to an image shake correction apparatus that performs image shake correction, an imaging apparatus including the image shake correction apparatus, and a control method for the image shake correction apparatus .

In recent years, there has been an increasing demand for an image pickup apparatus that includes an image shake correction apparatus that optically corrects the shake of the image pickup apparatus and that can perform high-quality shooting. Some image blur correction apparatuses displace a correction lens or an image sensor serving as a correction unit in accordance with a signal from a shake detection unit such as a gyro sensor to suppress image blur on an imaging plane. Patent Document 1 discloses an imaging apparatus that performs image blur correction using a step motor as a drive source.
Japanese Patent Laid-Open No. 2006-129597

  The shake generated in the imaging apparatus includes shakes including various speed components, such as a shake with a large shake amount and a fast speed and a shake amount with a small shake amount and a high frequency. In order to correct the image blur caused by the shake against such a shake, it is required to drive the correction lens or the image pickup device at a high speed and with high accuracy.

  In Patent Document 1, in order to prevent step-out of the step motor, the maximum speed of the motor is regulated by limiting the drive pulse time interval or the number of drive pulses within a predetermined sampling time.

  Further, the maximum speed of the correction lens or the image sensor and the minimum positioning resolution corresponding to one pulse of the step motor are determined by the reduction ratio of the transmission mechanism. Therefore, when the reduction ratio is reduced so as to follow fast shake and the maximum speed of the correction lens or the image sensor is set high, the minimum positioning resolution becomes coarse and the image correction accuracy decreases. In addition, when the reduction ratio is increased to increase the image correction accuracy and the minimum positioning resolution is set finely, the maximum speed of the correction lens or the image sensor is slowed down and cannot follow fast shake. Accordingly, when image blur correction is performed for shakes including various velocity components, there is a possibility that sufficient image blur correction accuracy cannot be maintained.

(Object of invention)
An object of the present invention is to provide an image shake correction apparatus , an imaging apparatus, and an image shake correction apparatus control method that enable highly accurate shake correction for shakes including various velocity components.

To achieve the above object, an image shake correction apparatus according to the present invention includes a shake detection unit that detects a shake, and a correction unit that corrects the image shake caused by the shake based on an output of the shake detection unit. A control means for generating a drive signal for moving the motor, a motor for moving the correction means, a rotor position detection means for detecting the rotor position of the motor, and an output of the motor according to the output of the rotor position detection means First driving means for switching the energization state of the coil, second driving means for switching the energization state of the coil of the motor in accordance with a predetermined time interval, and switching means for switching between the first driving means and the second driving means has the door, said switching means, indicating greater than a threshold value fluctuation rate signal is determined in advance from the shake detection unit selects said first driving means Otherwise it is characterized in that to select the second driving means.

  Similarly, in order to achieve the above object, an imaging apparatus provided with the image blur correction apparatus of the present invention is provided.

  According to the present invention, it is possible to provide an image shake correction apparatus or an imaging apparatus that enables highly accurate image shake correction with respect to shake including various velocity components.

  The best mode for carrying out the present invention is as shown in Examples 1 and 2 below.

  FIG. 1 is a diagram illustrating a circuit configuration of an image blur correction apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 101 denotes a gyro sensor, which detects a shake generated in the imaging apparatus and outputs a shake angular velocity signal. A control unit 102 calculates a driving condition of a motor 106 (described later) necessary for image blur correction from a shake angular velocity signal from the gyro sensor 101, and outputs a drive signal. The drive signal is composed of a drive pulse number or drive pulse interval (drive frequency) and a motor rotation direction.

  When speed control is used as a control method in the control unit 102, a driving speed of a motor 106 to be described later is based on a target speed of a correction unit (not shown) calculated by multiplying a deflection angular speed signal by a predetermined coefficient. And a drive signal corresponding to the drive speed is output. When position control is used, driving of a motor 106 described later is performed based on a target position of a correction unit (not shown) calculated by integrating a value obtained by multiplying a shake angular velocity signal by a predetermined coefficient by an integrator. The amount is obtained and a drive signal corresponding to the drive amount is output.

  Reference numeral 103 denotes a switching unit, which selects a driver unit (described later) used to drive the motor 106 in accordance with a shake angular velocity signal from the gyro sensor 101 and outputs a driving signal A or a driving signal B, which will be described later. The drive system of the motor 106 is switched. The drive signal A and the drive signal B are determined according to specifications of a brushless drive driver unit 104 (to be described later) and a step drive driver unit 105 (to be described later) based on a drive signal output from the control unit 102.

  A brushless drive driver unit 104 outputs a drive pulse for driving a motor 106 to be described later in response to a drive signal A output from the switching unit 103. At that time, the output timing of the drive pulse is controlled in accordance with a rotor position signal output from a first position sensor 107 and a second position sensor 108 described later. A step drive driver unit 105 outputs a drive pulse for driving a motor 106 described later in accordance with a drive signal B output from the switching unit 103. At that time, the output timing of the drive pulse is controlled according to the drive pulse interval (drive frequency) determined by the drive signal B.

  A motor 106 is driven by a drive pulse output from the brushless drive driver unit 104 or the step drive driver unit 105 and displaces a correction unit (not shown) via a power transmission mechanism (not shown) to Correct image blur. Reference numeral 107 denotes a first position sensor, and reference numeral 108 denotes a second position sensor, which outputs a rotor position signal of the motor 106. In the first embodiment, the type of the position sensor is not limited, and a Hall element may be used or an optical sensor may be used.

  Although FIG. 1 shows a configuration in which one gyro sensor 101 and one motor 106 are used to correct image blur in one direction, a plurality of motors are controlled from signals from a plurality of gyro sensors to correct blur in multiple directions. It is also possible to configure.

  In the first embodiment, the correction unit (not shown) driven by the motor 106 may be a correction lens or an image sensor. Further, the image blur on the imaging plane may be corrected by driving the entire optical system by the motor 106.

  FIG. 2 is a perspective view showing configurations of the motor 106, the first position sensor 107, and the second position sensor 108 of FIG. For the sake of explanation, some parts are shown broken away.

  The motor 106 includes a rotor 202 including a magnet 201, a first coil 203a, a second coil 203b, a first yoke 204a, a second yoke 204b, a first position sensor 107, and a second position sensor 108. Among these, the first coil 203a, the second coil 203b, the first yoke 204a, the second yoke 204b, the first position sensor 107, and the second position sensor 108 constitute a stator.

  The magnet 201 is a cylindrical permanent magnet whose outer periphery is multipolarly magnetized. It has a magnetization pattern in which the strength of the magnetic force in the radial direction changes in a sinusoidal shape with respect to the angular position. The rotor 202 is rotatably supported with respect to the stator and is fixed integrally with the magnet 201. The first yoke 204a has a plurality of magnetic pole teeth that are excited by the first coil 203a. By switching the excited pole, the torque applied to the rotor 202 can be changed. The first position sensor 107 and the second position sensor 108 are Hall elements that detect the magnetic flux of the magnet 201 and output a signal whose phase is shifted by 90 degrees in electrical angle. Here, if the number of poles of the magnet 201 is n, the electrical angle 360 ° corresponds to the actual rotor angle 720 / n °.

  The motor 106 can perform step driving using the step driving driver unit 105. That is, the step drive driver unit 105 rotates the rotor 202 at a desired speed by sequentially switching energization of the first coil 203a and the second coil 203b according to the input drive pulse interval (drive frequency) and the rotation direction. It is possible to make it. Further, it is possible to rotate the rotor 202 by a desired angle in accordance with the input drive pulse number. Therefore, even if the control unit 102 is a speed control method or a position control method, image blur correction can be performed by a step drive method.

  In step drive, speed control is possible by the input drive pulse interval. In addition, accurate positioning is possible even at low speeds. However, if the drive pulse interval is reduced (drive frequency is increased), the rotor 202 cannot respond to switching of coil energization, and the possibility of causing a step-out increases. For this reason, it is necessary to add a lower limit to the drive pulse interval and to allow for a predetermined safety factor with respect to the actual load, which limits driving at a high speed.

  In addition to the step drive described above, the motor 106 can perform brushless drive that uses the brushless drive driver unit 104 to switch the energization timing according to signals output from the first position sensor 107 and the second position sensor 108.

  FIG. 3 is a diagram illustrating sensor signal processing during brushless driving.

  As described above, since the strength of the magnet 201 in the radial direction is magnetized so as to be approximately sinusoidal with respect to the electrical angle, the first position sensor 107 shows a substantially solid sinusoidal solid line. A position signal A is obtained. Further, since the second position sensor 108 is arranged with a phase of 90 ° in electrical angle with respect to the first position sensor 107, the second position sensor 108 can obtain a position signal B indicated by a thin solid line in the form of a cosine wave.

  With respect to these position signals A and B, signals given advance angle α are advance signals A and B indicated by broken lines. Further, signals obtained by binarizing the advance signals A and B are binarized signals A and B indicated by alternate long and short dash lines. The energization of the first coil 203a is switched based on the binarized signal A, and the second coil 203b is switched based on the binarized signal B. It is possible to change the characteristics of the motor 106 by controlling the advance angle α.

  The brushless drive driver unit 104 switches the energization of the first coil 203a and the second coil 203b based on the above-described binarized signals A and B in accordance with the input drive pulse number and rotation direction, so that the rotor It is possible to rotate 202 by a desired angle. Further, by controlling the current applied to the motor 106, the rotor 202 can be rotated at a desired speed. Further, if the number of driving pulses is switched at predetermined time intervals, the rotor 202 can be rotated at a desired speed. That is, image blur correction can be performed by the brushless drive method regardless of whether the control unit 102 is a speed control method or a position control method.

  In brushless driving, the energization is switched while detecting the position of the rotor 202, so that no step-out occurs if appropriate control is performed. Therefore, there is no need to limit the driving speed or to anticipate the safety factor as in step driving. In addition, since it is possible to drive with high speed and high efficiency with respect to step driving, it is possible to correct image blur even when the shake speed is high. However, when speed control is performed using current, the current decreases during low-speed driving and the torque decreases, so the positioning accuracy at low speed decreases. In addition, since the closed loop control is performed in which the control is performed while always detecting the rotor position, the load on the control unit 102 is larger than the step drive that is the open loop control.

  In the first embodiment, the magnetic flux of the rotor magnet is detected by a magnetic sensor (Hall element), and the energization timing is controlled. However, the method for detecting the rotor position is not limited. A detection magnet that is displaced with the rotation of the rotor may be arranged and detected, or the light shielding plate and the pattern surface may be read by an optical sensor. Further, the position sensor may be fixed integrally with the motor, or may be fixed to a member different from the motor.

  Next, the operation of the switching unit 103 provided in the image shake correction apparatus according to the first embodiment will be described with reference to the flowchart of FIG.

  When the switching operation is started, first, in step S301, the drive signal output from the control unit 102 is acquired. Then, in the next step S302, the shake angular velocity ω from the gyro sensor 101 is acquired. In the subsequent step S303, the absolute value | ω | of the deflection angular velocity is compared with a predetermined threshold value SH1.

  As a result of the comparison, if the absolute value | ω | of the shake angular velocity exceeds a predetermined threshold value SH1, the process proceeds to step S304, and a drive signal is output to the brushless drive driver unit 104. If the absolute value | ω | of the shake angular velocity does not exceed the predetermined threshold value SH1, the process proceeds to step S305, and a drive signal is output to the step drive driver unit 105. That is, when correcting a relatively slow shake, a step drive capable of accurate positioning even at a low speed is used, and when correcting a relatively fast shake, a brushless drive capable of being driven at a high speed is used.

  FIG. 5 is a schematic diagram showing the relationship between the shake angular velocity and the shake correction performance for each drive method.

  In FIG. 5, Pmin is a lower limit value of the target correction performance, and ωmax is a target upper limit value of the shake angular velocity that can be corrected. ST indicates the correction performance at the time of step driving, and ω1 is the maximum angular velocity that can follow the shake. As described in the explanation of the step driving method, ω1 is determined by the limitation of the driving pulse interval (driving frequency) provided to prevent the step-out. In the condition of FIG. 5, when the deflection angular velocity is ω1 or less, sufficient correction performance is maintained. However, when the shake angular velocity exceeds ω1, it becomes impossible to follow the shake, the correction performance suddenly decreases, and falls below the target performance Pmin just before ωmax of the target angular velocity.

  ST ′ shows the correction performance at the time of step driving when the reduction ratio is made smaller than ST in order to widen the correction area, and ω1 ′ shows the maximum angular velocity that can follow the shake. Since the reduction ratio is reduced, ω1 ′ exceeds the target shake angular velocity ωmax, but the minimum resolution corresponding to one step becomes rough, so that the overall correction performance is reduced and is lower than the target performance.

  BL indicates the correction performance at the time of brushless driving. The reduction ratio is the same as the ST condition, and shows sufficient correction performance in the high speed range. However, as described in the description of the brushless driving method, since the current value applied to the motor is low during low speed control, sufficient positioning accuracy cannot be maintained due to torque reduction, and the correction performance deteriorates. In FIG. 5, when it is less than ω2, the correction performance is lowered, and the correction performance is lower than ST.

  Therefore, in the first embodiment, a threshold value SH1 is set so that ω1> SH1> ω2, and step driving is performed at low speed and brushless driving is performed at high speed. Thus, the target performance can be satisfied over the entire target correction area. Therefore, in the image shake correction apparatus according to the first embodiment, it is possible to perform high-precision image shake correction for shakes including various speed components. In particular, the present invention is useful for an image blur correction apparatus that is used in an interchangeable lens for a single-lens reflex camera that requires a wide correction range (correction frequency range) and high image blur correction performance.

  Note that the threshold value of the switching unit 103 can have hysteresis. FIG. 6 is a flowchart showing another operation of the switching unit 103 in this case.

  When the switching operation is started, first, in step S401, the drive signal output from the control unit 102 is acquired. In the next step S402, the shake angle signal ω output from the gyro sensor 101 is acquired. In a succeeding step S403, the current driving method held in the memory in the switching unit 103 is acquired.

  When the acquired current driving method is the step driving method, the process proceeds from step S404 to step S405, and the absolute value | ω | of the shake angular velocity is compared with a predetermined threshold value SH1. If the absolute value | ω | of the shake angular velocity exceeds the predetermined threshold value SH1 as a result of the comparison, the process proceeds to step S406, and a drive signal is output to the brushless drive driver unit 104. If the absolute value | ω | of the shake angular velocity does not exceed the predetermined threshold value SH1, the process proceeds to step S407, and a drive signal is output to the step drive driver unit 105. Thereafter, the process proceeds to step S411, where the current driving method held in the memory in the switching unit 103 is updated, and the switching operation is terminated.

  If the current driving method is the brushless driving method, the process proceeds from step S404 to step S408, and the absolute value | ω | of the deflection angular velocity is compared with a predetermined threshold value SH2. If the absolute value | ω | of the shake angular velocity exceeds the predetermined threshold value SH2 as a result of the comparison, the process proceeds to step S409, and a drive signal is output to the brushless drive driver unit 104. If the absolute value | ω | of the shake angular velocity does not exceed the predetermined threshold value SH2, the process proceeds to step S410, and a drive signal is output to the step drive driver unit 105. Thereafter, the process proceeds to step S411, where the current driving method held in the memory in the switching unit 103 is updated, and the switching operation is terminated.

Here, the maximum angular velocity that can follow the shake by step driving is ω1, the minimum angular velocity that can be corrected by brushless driving is ω2, and the thresholds SH1 and SH2 are set to ω1>SH1>SH2> ω2.
Set within the range. In other words, by changing the threshold value according to the current driving method, it is possible to give hysteresis to selection of the driving method, stabilize the switching operation, and perform highly accurate image blur correction.

  The image shake correction apparatus according to the first embodiment includes the gyro sensor 101 that detects shake. Further, the control unit 102 generates a drive signal for displacing the optical element in order to correct image blur caused by the shake based on the shake angular velocity ω from the gyro sensor 101. Furthermore, it has the 1st position sensor 107 and the 2nd sensor 108 which detect the rotor position of the motor 106 for displacing an optical element. Further, the brushless drive driver unit 104 switches the energization state of the coils 203a and 203b of the motor 106 in accordance with the outputs of the first position sensor 107 and the second position sensor 108 based on the drive signals. Further, it has a step drive driver unit 105 that switches the energization state to the coils 203a and 203b of the motor 106 in accordance with a determined time interval based on the drive signal. Furthermore, it has the switching part 103 which switches the brushless drive driver part 104 and the step drive driver part 105. FIG.

  The switching unit 103 switches between the brushless drive driver unit 104 and the step drive driver unit 105 in accordance with the shake angular velocity ω (specifically, absolute value | ω |) from the gyro sensor 101.

  Specifically, as shown in FIG. 4, the switching unit 103 switches to the brushless drive driver unit 104 when the deflection angular velocity ω is greater than a predetermined threshold value SH1, otherwise it is step driven. Switching to the driver unit 105 is performed.

  Alternatively, the threshold value SH1 which is the first threshold value and the threshold value SH2 which is the second threshold value which is smaller than the threshold value SH1 are previously provided as the threshold value. Then, as shown in FIG. 6, the switching unit 103 switches to the brushless drive driver unit 104 when the deflection angular velocity ω changes from a value smaller than the threshold value SH1 to a value larger than the threshold value SH1. Further, when the deflection angular velocity ω changes from a value larger than the threshold value SH2 to a value smaller than the threshold value SH2, switching to the step drive driver unit 105 is performed.

  Therefore, it is possible to provide an image shake correction apparatus that enables highly accurate image shake correction with respect to shakes including various velocity components, and an imaging apparatus including the image shake correction apparatus.

  FIG. 7 is a diagram illustrating a circuit configuration of the image shake correction apparatus according to the second embodiment of the present invention, and a description will be given of points different from the image shake correction apparatus according to the first embodiment.

  A control unit 201 calculates a driving condition of the motor 106 necessary for image blur correction from a shake angular velocity signal from the gyro sensor 101, and outputs a drive signal. The drive signal is composed of a drive pulse number or drive pulse interval (drive frequency) and a motor rotation direction. Further, the control unit 201 outputs a deviation (difference amount) between a target position of a correction unit (not shown) calculated from a shake angular velocity signal and a current position of the correction unit. The current position of the correction means may be a value obtained by holding the integrated value of the drive signal in the memory, or may be calculated using the outputs of the first position sensor 107 and the second position sensor 108. Further, the position of the correction unit may be directly detected using a position sensor different from the first position sensor 107 and the second position sensor 108.

  Reference numeral 202 denotes a switching unit, which drives the motor 106 in accordance with a deflection angular velocity signal output from the gyro sensor 101 and a deviation (difference amount) between the target position of the correction unit output from the control unit 201 and the current position. The driver unit to be used is selected and the drive signal A or drive signal B is output. As a result, the driving method of the motor 106 is switched. The drive signal A and the drive signal B are determined based on the specifications of the brushless drive driver unit 104 and the step drive driver unit 105 based on the drive signal from the control unit 201.

  The explanation about the other components shown in FIG. 7, the explanation about the configuration of the motor 106, the first position sensor 107, and the second position sensor 108, the explanation about the step driving, and the explanation about the brushless driving are the same as those in the first embodiment. Since it is the same, the description is omitted.

  Next, the operation of the switching unit 202 provided in the image shake correction apparatus according to the second embodiment will be described with reference to the flowchart of FIG.

  When the switching operation is started, a drive signal from the control unit 201 is first acquired in step S501. Then, in the next step S502, the shake angle signal ω output from the gyro sensor 101 is acquired. In subsequent step S503, the deviation dx between the target position of the correction means output from the control unit 201 and the current position is acquired.

  In the next step S504, the function f (ω, dx) using the deflection angular velocity ω and the deviation (difference amount) dx as parameters is compared with a predetermined threshold value SH3. As a result of the comparison, if the function f (ω, dx) exceeds the threshold value SH3, the process proceeds to step S505, and a drive signal is output to the brushless drive driver unit 104. If the function f (ω, dx) does not exceed the threshold value SH3, the process proceeds to step S506, and a drive signal is output to the step drive driver unit 105.

  The function f (ω, dx) assumes that the deflection angular velocity ω is constant, and the deviation dx is less than or equal to a predetermined allowable value when the correction unit performs the correction operation at the maximum angular velocity that can be followed by the step drive method. It shows the required time to become. The threshold value SH3 is set to an allowable follow time. Further, as shown in the first embodiment, the threshold value may have hysteresis.

  FIG. 9 is an explanatory diagram of the shake correction operation in the second embodiment at a certain time S0. Here, it is assumed that shake correction control is performed by position control.

  At time S0, the deflection angular velocity is ω0, and the deviation between the target position and the current position is dx0. It is assumed that the deflection angular velocity ω0 at S0 is constant thereafter. Xobj is a target position.

When the image blur correction operation is performed on the target position by the brushless driving method, the tracking operation is performed along XA at the angular velocity ωA corresponding to the current applied to the motor 106, and the target position is reached at time SA. At this time, the required time TA to reach the target position is TA = | dx0 / (ωA−ω0) |
It is expressed by the following formula.

When the correction operation is performed on the target position by the step driving method, the tracking operation is performed along XB at the maximum angular velocity ωB regulated by the step driving driver unit 105, and the target position is reached at time SB. At this time, the required time TB to reach the target position is TB = | dx0 / (ωB−ω0) |
It is expressed by the following formula.

  Here, consider the case where f (ω, dx) = TB. In this case, since f (ω, dx)> SH3, a drive signal is output to the brushless drive driver unit 104 in step 505 in FIG. 8, and the correction unit performs a follow-up operation along XA to correct image blur. Done.

  In the image blur correction operation, the follow-up required time TA or TB is regarded as a follow-up delay, and the longer the follow-up time TA or TB, the lower the image blur correction accuracy. When the deviation between the target position and the current position has become large due to exceptionally high vibration that cannot be followed even with the brushless drive method, the follow-up time is made as short as possible to return to the follow-up operation. Must.

  The image shake correction apparatus according to the second embodiment includes the gyro sensor 101 that detects shake. Further, the control unit 201 generates a drive signal for displacing the correction unit to correct the image blur caused by the shake based on the shake angular velocity ω from the gyro sensor 101. Furthermore, it has the 1st position sensor 107 and the 2nd position sensor 108 which detect the rotor position of the motor 106 for displacing a correction | amendment means. Further, the brushless drive driver unit 104 switches the energization state of the coils 203a and 203b of the motor 106 in accordance with the outputs of the first position sensor 107 and the second position sensor 108 based on the drive signals. Further, it has a step drive driver unit 105 that switches the energization state to the coils 203a and 203b of the motor 106 in accordance with a determined time interval based on the drive signal. Furthermore, it has the switching part 202 which switches the brushless drive driver part 104 and the step drive driver part 105. FIG.

  Then, the switching unit 202 switches between the brushless drive driver unit 104 and the step drive driver unit 105 in accordance with the shake angular velocity ω (specifically, absolute value | ω |) from the gyro sensor 101.

  Specifically, the control unit 201 calculates the target position of the correction unit from the shake angular velocity ω from the gyro sensor 101, calculates the current position of the correction unit, and displaces the correction unit to the target position based on the target position and the current position. A drive signal for generating the signal is generated. Further, the switching unit 202 switches between the brushless drive driver unit 104 and the step drive driver unit 105 according to not only the shake angular velocity ω from the gyro sensor 101 but also the difference amount between the current position and the target position. Yes. Note that the current position of the correction means is calculated using, for example, a value obtained by holding the integrated value of the drive signal in the memory or using the outputs of the first position sensor 107 and the second position sensor 108.

  Alternatively, the switching unit 202 calculates a required time until the difference amount becomes smaller than a predetermined allowable difference amount from the difference amount between the shake angular velocity ω, the current position, and the target position. If the required time is longer than a predetermined time, the operation is switched to the brushless drive driver unit 104. Otherwise, the operation is switched to the step drive driver unit 105.

  As described above, in the second embodiment, when the follow-up required time exceeds the allowable value in the step driving method, the driving method is switched to the brushless driving method. Therefore, it is possible to perform highly accurate image blur correction for shakes including various velocity components.

  In the first and second embodiments, the case where the characteristic configuration of the present invention is applied to an image shake correction apparatus and an image pickup apparatus including the image shake correction apparatus has been described. However, the present invention is not limited to this, and the characteristic configuration of the present invention can also be applied to a motor drive device.

  In this case, the motor drive device includes a motor, target output means (equivalent to the control units 102 and 201) that outputs a speed signal that is a target of the motor, and a position sensor that detects the rotor position of the motor. To do. Further, the first driving means for switching the energization state of the motor coil in accordance with the output of the position sensor based on the speed signal, and the motor coil in accordance with a predetermined time interval based on the speed signal. And a second driving means for switching the energization state of the power source. Furthermore, it shall have the switching means (equivalent to the switching parts 103 and 202) which switches a 1st drive means and a 2nd drive means. The switching means switches between the first driving means and the second driving means in accordance with the speed signal from the target output means.

  By using the motor driving device having the above-described characteristic configuration, it is possible to switch the driving means according to the speed signal that is the target of the motor. In other words, it is possible to provide a motor drive device that can use one motor as drive means suitable for various speeds.

(Correspondence between the present invention and the embodiment)
The gyro sensor 101 corresponds to the shake detection means of the present invention. Further, the control unit 102 corresponds to a control unit that generates a drive signal for moving the correction unit in order to correct the image blur caused by the shake based on the output from the shake detection unit of the present invention. The controller 102 is the target output means of the present invention, the first position sensor 107 and the second position sensor are the rotor position detecting means of the present invention, the motor 106 is the motor of the present invention, and the coils 203a and 203b are the present invention. Correspond to the coils respectively. Further, the brushless driving driver unit 104 corresponds to the first driving unit of the present invention, the step driving driver unit 105 corresponds to the second driving unit of the present invention, and the switching unit 103 corresponds to the switching unit of the present invention. Further, the correction lens or the image sensor corresponds to the correction means of the present invention.

  Further, the shake angular velocity signal corresponds to the shake signal of the present invention, and the threshold value SH1 corresponds to a predetermined threshold value. The threshold value SH1 corresponds to the first threshold value of the present invention, and the threshold value SH2 corresponds to the second threshold value. Further, the drive signal corresponding to the drive speed output by the control units 102 and 201 corresponds to the target speed signal of the present invention.

1 is a block diagram illustrating a configuration of an image shake correction apparatus according to Embodiment 1 of the present invention. It is a perspective view which shows the structure of the motor of FIG. It is a figure which shows the sensor signal process at the time of brushless drive in the image blurring correction apparatus of FIG. 3 is a flowchart illustrating an operation of a switching unit in the image shake correction apparatus of FIG. 1. FIG. 2 is a schematic diagram illustrating a relationship between a shake angular velocity and a shake correction performance according to the image shake correction apparatus of FIG. 1. 7 is a flowchart showing another operation of the switching unit in the image shake correction apparatus of FIG. 1. It is a block diagram which shows the structure of the image blur correction apparatus which concerns on Example 2 of this invention. FIG. 8 is a diagram for explaining an image blur correction operation of the image blur correction apparatus in FIG. 7. It is explanatory drawing of the shake correction operation | movement which concerns on Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Gyro sensor 102 Control part 103 Switching part 104 Brushless drive driver part 105 Step drive driver part 106 Motor 107 1st position sensor 108 2nd position sensor 201 Magnet 202 Rotor 203a, 203b Coil 204a, 204b Yoke

Claims (6)

Shake detection means for detecting shake;
Control means for generating a drive signal for moving the correction means to correct image shake caused by the shake based on the output of the shake detection means;
A motor for moving the correction means;
Rotor position detecting means for detecting the rotor position of the motor;
First driving means for switching the energization state of the motor coil in accordance with the output of the rotor position detecting means;
Second driving means for switching the energization state of the motor coil according to a determined time interval;
Switching means for switching between the first driving means and the second driving means;
The switching means selects the first drive means when the shake speed signal from the shake detection means shows a value larger than a predetermined threshold value, and selects the second drive means otherwise. An image blur correction apparatus characterized by: The threshold value includes a first threshold value and a second threshold value smaller than the first threshold value,
Speed said switching means, said deflection rate signal is, if changed to the first threshold value greater than the said first threshold value smaller than by selecting the first driving means, said deflection 2. The image according to claim 1 , wherein when the signal changes from a value larger than the second threshold value to a value smaller than the second threshold value, the second driving means is selected. Shake correction device. The control means calculates a target position of the correction means from the shake speed signal, and calculates a difference amount between the target position and the current position of the correction means,
Said switching means, indicating greater than a threshold value function is determined in advance to the run-out speed signal and said difference amount parameter, selects the first drive means, otherwise the second image blur correction device according to any one of claims 1 or 2, characterized by selecting a drive means. The switching means calculates a required time until the difference amount becomes smaller than a predetermined allowable difference amount from the deflection speed signal and the difference amount, and when the required time is larger than a predetermined time, 4. The image blur correction apparatus according to claim 3 , wherein the first driving unit is selected, and if not, the second driving unit is selected . An image pickup apparatus comprising the image shake correction apparatus according to claim 1 . Based on the output of the shake detection means, a shake detection means for detecting shake, a control means for generating a drive signal for moving the correction means to correct image shake caused by the shake, and moving the correction means And a rotor position detecting means for detecting the rotor position of the motor, a first drive means for switching the energization state of the motor coil in accordance with the output of the rotor position detecting means, and a predetermined time A control method for controlling an image blur correction device comprising: a second drive unit that switches a current-carrying state of the motor coil according to an interval;
A switching step of switching between the first drive means and the second drive means;
In the switching step, if the shake speed signal from the shake detection means shows a value larger than a predetermined threshold value, the first drive means is selected, and if not, the second drive means is selected. And a control method for the image blur correction apparatus .

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